Improvement in dovetailing-machines



UNITED STATE JOHN B. BITCHES@ OF POMEROY, OHIO.

Specification forming part of Letters Patent No. 117,332, dated July 25,1871.

To all vwhom it may concern:

Be it known that I, JOHN B. lirrcnnr, of Pomeroy, in the county of Meigsand State of Ohio, have invented a new and Improved Dovetailing-Machine;and I do hereby declare that the following is afull, clear, and exactdescription thereof, which will enable others skilled in the art to makeand use the same, reference being had to the a-ccompanying drawingforming part of this specification.

My invention consists in improving dovetailing-machines, as hereinafterdescribed and subsequently pointed out in the claims.

Figure l isa transverse sectional elevation through the table and a partof the cutterframe. Fig. 2 is a longitudinal sectional elevation ofthetable. Fig. 3 is a plan view of the improved spring-bar used on thetable in connection with the adjustable blocks for spacing the work andholding the table. Fig. 4 is a pla-n of the table and a part of thecutterframe- Fig. 5 is a plan of the adjusting-blocks and theiradjuncts. Fig. 6 is a perspective view of one of the adjustable blocksused in connection with the spring-bar for spacing. Fig. 7 is aperspective view ofthe end piece of the drawer fitted for joining withthe front. Fig. S is a perspective view of the drawer front as I proposeto prepare it with this improved machine for the reception ofthe endpiece, Fig. S.

Similar letters of reference indicate corresponding parts.

A is the revolving cutter, mounted in a vertically-reciprocatin g frame,B, and C is the table whereon the work is to be Vpresented to themachine. rFhis table, having the boards to be dovetailed clamped uponit, has to be moved along past the cutter the distance from center tocenter of the tenons or mortises, and held while the cutter moves up ordown through the board when laid atwise to do its work 5 and as thedistances between centers vary in different work, it be comes necessaryto employ adjustable spacing devices iu connection with the table forthe purpose. These consist, as described in the afore` mentionedapplication, in the adjustable blocks D, arranged in the slotted bar E,and having the wedge F between them, by which they are shifted closertogether or further apart, as may be re quired by the work in hand, thesaid wedges being driven in or drawn back by the plate G will regulateor gauge the position of the table.

In this example I propose to make use of the same instrumentaliti es,with the following modifications: I now propose to notch the blocks D onone side, as shown at L, and lit the wedges in them to hold them down,instead of employing viianges on the lower ends of the blocks, similarto those,l M, at the top, and working under the bar E, which simplifiesthe construction of the blocks, and admits of arranging the said barclose upon the upper face of plate G, which is preferable; and insteadof making the blocks with beveled upper ends, N, and the block K with abeveled lower' side for riding' over them and bearing against one sideof the blocks, I propose to make the block tops N and the block K lwitha flat under side, so that it will act alike against either side of theblocks to stop the movement in either way, when required. I also nowpropose to make the block K wedge-shaped, and to attach the spring-bar Ito the table at N by a screw passing through a curved slot, or in anyother equivalent way, whereby it may be adjusted laterally, so thatafter the blocks l) have been adjusted and it is found that the tenen isspaced a little too large or too small, as the ease may be, for fittingthe mortise snugly, a slight variation can be produced by so shiftingthe spring-pawl as to cause the wedge to bear iearer to or further fromthe point, which will have the effect to lengthen orshorten the spaces,the table being shifted along so that the opposite edge of wedge K tothat bea-rin g against one stud N, while forming one side ofthe tenon,bears against the side of the next stud, instead of shiftin t-he wet geover one stud, N, to the same side of the next one, as in theaforementioned invention. The end O of the said spring-lever is to beconnected to a cranked lever on the top of the table, the same way as inthe aforementioned case, for raising the block K above the block D tolet the table be moved along. In order to provide drawer-frontdovetails, such as is shown in. Fig. E), the piece to be worked must beheld vertically on the table, so that the cutter may work up and downalong the side of the piece,

cutting partly through it, while the end to be dovetailed rests on thetable of the machine. For this purpose I provide the clamp shown in planin Fig. 5 and in section, Fig. l, which consists of the front plate a,the sides b, cross-piece e, flanges d, and clamp-screw f, the saidflanges having long vertical slots g to be clamped adjustably to thetable, by which the clamp may be adjusted toward or from the cutter togauge the cut to the required depth. The said clamp may have astop-screw, 7a, by which to adjust the piece so as to make the iirsttenon the right thickness.

The mode of operation in making the drawer- Jfront dovetails is asfollows: The movable blocks D N are adjusted so as to make the requirednumber of mortises in the drawer ends, Fig. S, and the 'piece to be cutbeing clamped on the table ilatwise, the cutter is caused to pass downthrough it in the same manner as in the aforesaid invention, therebyforming the notches Z.V This being done, the apparatus for clamping thestuff atwise to the table being removed, and the clamp, Figs. l and 5,being attached to the table, also the piece for the drawer being clampedin it as shown, with the end to be dovetailed resting on the table butprojecting over the edge of it as much or a little more than the depthof the mortises to be made, the spring-bar I and its wedge K are thenproperly adjusted against one of the blocks D N, and the cutter israised to act on the work, and forms one side of the tenon Q, Fig. 9.The cutter is then lowered out of the stuff, and the table is moved sothat the side of the block K opposite to that which was against a blockD N is shoved against the next block. The cutter is again raised, makinganother cut and forming one side of the second operations are repeateduntil all the cavities S` are formed. Should the tenons of Fig. 9 iittoo loosely in the notches of Fig. 8, it is only neces- 'sary to movethe wedge-shaped block K of bar I a little in the direction to bring awider part of the wedge against the blocks D N, by which the size ofthespaces will be reduced and the size of the tenons increased; and shouldthey fit too tightly they will be connected by the opposite movement ofthe bar I. Thus it will be seen that very slight changes, very simpleand easy to make, a perfect iit ofthe dovetail is secured.

Having thus described my invention, I claim as new and desire to secureby Letters Patentl. The adjustable spacing blocks D, having a groove, L,in one side, and a spacing wedge, F, itted therein for holding saidblocks against being raised, substantially as specied.

2. The springbar I, arranged for lateral adjustment at its connectionwith the table, and provided with the wedge-shaped stop-block K, and theadjustable spacing -blocks D having the studs N thereofl arranged foroperation in conjunction with the said wedge-shaped block K, allsubstantially as specified.

. JOHN B. RITCHEY.

Vit-nesses:

A. Q. Ross, W. H. MEREDITH.

